Quoted from HowardR:

The Tilt (T) relay should only be energized when one of the tilt switches is closed.

Quoted from D-Gottlieb:

This machine normally will be in tilt mode at power on. The backbox lights should be on, playfield lights off, game over light on, coin entrance lights on.

Quoted from D-Gottlieb:

The ball should not eject unless resetting the machine. Upon resetting, the playfield lights will light. The AX relay is the heart of the reset sequence and is quite sensitive to proper adjustment. Ensure that it is correctly working before messing with the score motor or anything else. You can also check the coin detect. If they stick, it will cycle endlessly. Does the score reset at all?

Quoted from D-Gottlieb:

The switch you point out is one of a few slam switches designed to prevent the cabinet from being picked up and dropped. If this switch is opened at all during a game, the game ends. The tilt switches are located below the left flipper button. There is a pendulum and a ball switch.

Quoted from HowardR:

Yes

Quoted from AlexF:

I just got one of these running for a friend a few months back. The root of all it's problems were related to the AX relay. It was a real fussy one too.

Quoted from AlexF:

You know I didn't have a schematic to work with. I usually like the shotgun approach. Go through clean and adjust everything properly and it should work. That usually gets you close but you also discover things with that strategy. I found a disconnected wire on the AX and thought that would do it but there was more going on. I seem to remember the "O" relay and the AX being a combined problem with my start sequence.
What helped me most was reading a couple troubleshooting posts related to the start-up sequence for 300 on RGP. I think someone had a similar problem as I did. Posted by the late great Al Warner if I remember correctly.
Guys willing to help with a schematic can usually get you narrowed down to specific areas to focus on. That helps a lot if you want to fast-track it.

Quoted from rolf_martin_062:

Hi WhiskeyTango +
I am irritated by the words You use in post-1 --- You "push the plastic down on the Tilt-Hold-Relay and the GI comes on" --- This is a good work-around and it helps --- but later on You write "The Tilt-Hold-Relay needs to be manually RESET every time I power on the pin / The Tilt-Relay is closed by default".
OK, there are the so-called Interlock-Type Relays (argh - the example AX-Relay) having two coils on the relay. The other relays having only one coil - when the pin is toggled-off: The relay is not pulling / is not activated / is not active / does not fire / (((we may say the relay is resetted))) --- When the pin is toggled-on and running: Such an relay may "get active / fires / pulls / pulls-in / constantly pulls / gets activated". Please use more words and describe the behaviour of the TILT-Relay - and the Tilt-Hold-Relay.
(((In such an modern pins the Game-Over-Relay and the First-Ball-Relay pull-in and stay pulling when we toggle-on the pin. The Tilt-Hold-Relay pulls-in and stays pulling when we start the very first game (after toggling-on) -- when the AX-Relay actuates at starting a game (and it does not harm when You manually actuate the armature and the Tilt-Hold-Relay then stays pulling).))) Greetings Rolf

Quoted from Toyguy:

Even if they reset to zero correctly, check your score reel switches. There are two reset switches per reel and both must work properly when the reel is at zero.

Quoted from HowardR:

Here's the circuit that deactivates the AX (Reset Control) relay.

Quoted from Toyguy:

If I'm remembering correctly, there are 2 reset switches on each score reel. One breaks the circuit to the associated points relay when zero is reached. That stops the reel from stepping. The other is in-circuit with the reset system so if that one is mis-adjusted the game will continue trying to reset and the score motor will continue to run even when the reels have stopped. Definitely get the P3 and P4 reels all checked out and she may just start.

Quoted from rolf_martin_062:

Hi WhiskeyTango
the snippet of schematics shows the stepping on the Player-Unit --- some steps and the Unit reaches position-20 - Z1 pulls-in and NOW the Score-Reels of Player-1 and -2 must reset ---then all the shown switches (Pl-1 and Pl-2) are resetted - Switches are closed --- the player-Unit can step one step --- so it reaches the position-21 --- and the Z2- Pl-3, -4 stuff happens.
Manually put that score-Drum into Zero-Position and JUMPER (closing permanently) the "Switch that is missing a blade) --- Only start and play ONE-Player-Games. Greetings Rolf

Quoted from D-Gottlieb:

Check the player unit in the backbox.

Quoted from D-Gottlieb:

It sounds like you have multiple issues throughout the machine. The springs rarely get weak, what happens is that the workings get mucked up and need cleaning. The score reels need to work correctly and reset. Going through every relay and switch is what you should try next. It is pointless to troubleshoot without first adjusting the various contacts.

Quoted from newmantjn:

Preach it brother....Truth. Weak spring = code for "Dirty gummed up crap in the mechanism"

Quoted from rolf_martin_062:

Hi WhiskeyTango
Start a new game and wait for "Score-Motor does turn endlessly" - NOW toggle-off the main power switch and unplug the line cord (Safety Reasons).
See the JPG --- the pin is in Home-Positon --- my green line is an extension of the switchblades on top of the black cam - cam sitting closest to the wood / towards the players. This black cam has only ONE tooth and in the Home-Position means also Zero-Position: The single tooth actuates its switchstack.
See in Your pin along the axis of the Player-Unit - some white cams and the last cam is the black cam. Do manually step --- about (7,8) 9 (10,11) steps and You reach Home-Position - see it (?).
Then step some 5,6,7 more steps (just to help the pin in the following start-up). Plug-in, toggle-on, start a new game --- the pin comes to the fault - Score-Motor is endlessly turning --- NOW, YOU carefully do these about (7,8) 9 (10,11) steps and You reach Home-Position --- big question: Does the pin kicks-out the ball and You can play a One-Player-Game ? Greetings Rolf

Quoted from D-Gottlieb:

There is a tilt switch attached to the underside of the playfield located near the middle that looks just like the bounce switch you asked about earlier, however this switch needs to be open, not closed. Check that switch.

Quoted from rolf_martin_062:

Hi WhiskeyTango +
Top to middle of the JPG shows the lights section --- ONLY of interest: The "encircled red switches" on H-Tilt-Hold-Relay --- the H-Relay should stay pulling forever so by that pulling these lights are always lit.
On the bottom of the JPG I show a way how the H-Relay could be pulsing (pulling - nonpulling - pulling etc.) --- the threebladed Make-and-Brake-Switch on H-Relay beeing faulty --- and the O-Relay steady pulling while the Score-Motor runs and runs and the SCM-1D therefore closes and opens.
BUT, but, but - You write "T-Tilt-Relay" activates and de-activates (and this makes the H-Relay do the same). Very strange.
I suggest: WhiskeyTango says "Want to bring my pin to life - by now I am NOT interested in the Tilt-Feature --- I simply unsolder the wire color-orange-white-red away from the coil of Tilt-Relay and so the Tilt-Relay cannot pull-in". The problem is not solved but put-off for a while.

Quoted from rolf_martin_062:

I am running into confusion --- The Score-Motor is running and You keep working on the Score-Motor. I say "maybe the Score-Motor does run forever because the Player-Unit sitting in the Backbox does faulty not step to Home-Position --- lets help the Player-Unit in the Backbox to step to Home-Position. So toggle-off again and manually step the Unit and look when You reach Home-Position --- then with some paint: MARK this Home-Position --- then when You have toggled-on again and the pin acts faulty: Toggle-off - step on the Player-Unit until You (again) reach Home-Position and tell us how many steps You had to step to (again) reach Home-Position. A picture is nice but not good enough.
Please do on the PLAYER-Unit sitting in the Backbox what I wrote (about) in post-35.

Quoted from rolf_martin_062:

Hi WhiskeyTango +
back to troubleshooting - in post-1 You wrote "I picked up a Gottlieb 300 ..." - this I read as "the pin has never been running in my possession".

Quoted from rolf_martin_062:

I look at the picture in post-39 - Your pin stops in this position (?) --- I look at the "JPG here, my Surf Champ in Home-Position" and the pictures are totally different. Maybe (maybe) an preowner tried to fix the pin - has taken-off the "Bakelite stuff turning" and mounted the bakelite stuff back again --- but mounted it "faulty / turned / twisted" ?
I refer to post-35 --- pin is toggled-off - then manually stepping the Player-Unit - step and step and step until the single, only tooth on cam-5, black cam actuates its switchstack --- THIS is Home-Position. And with the Unit in Home-Position: Take a picture and show us --- I would like to compare "Your picture to Come" with my pictures (HOME-Position).
SteveFury made an excellent topic: https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic --- in this post https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic/page/2#post-3312314 I posted a link to "Kerry Imming" - "Last Ball information" and also "General Information".

Quoted from rolf_martin_062:

In post-44 You still have the strange / faulty "T-Relay and H-Relay are pulsed" --- tell us about "intervals in between --- dependency on turning of the Score-Motor ? slow action or machine-gunning - rhythmically or accidentally --- write about.

Quoted from rolf_martin_062:

THEN unsolder the wire orange-white-red away from the "Coil of T-Tilt-Relay" so the T-Relay cannot pull-in. Plug-in the pin and manually press the armature of H-Hold-Relay - the relay should stay pulling forever.
THEN start a new game --- ifever the Score-Motor comes to an halt: Toggle-off the pin - manually step on the Player-Unit COUNTING the steps You must step to reach Home-Position (cam-5 actuates its switchstack) and tell us "HOW many steps You had to step to reach Home-Position" --- we THEN can figure out "in WHAT / WHICH position of the Player-Unit" Your pin has stopped. Greetings Rolf

Quoted from rolf_martin_062:

Do not get angry - a "mild reproach / animadvert" --- I suggested to (pin is toggled-off) manually step the Player-Unit to Home-Position AND THEN some steps more (1 or 2 or 3 ... 7 ... less than 18). The reason for this suggestion was / is: Sometimes / rare there is a minor fault in the pin --- starting a NEW game when the pin is in Home-Position: In This situation the pin does not start the new game. I want to be kind and helpful to the pin so I manually step a couple of steps beyond Home-Position - then I toggle-on and start a new game.

Quoted from rolf_martin_062:

I also would like to say "hooray" - but Your "pin goes completely around" irritates me a bit. Please toggle-off the pin - manually put some points on a Score-Drum of Player-1 --- maybe 100 or 200 points on the hundreds drum - or 1000 or 2000 points on the thousands drum - toggle-on and start a game --- big question: Does the pin acts "normal as we are used" - the Score-Drums will reset and then the pin steps further to Home-Position - and then the Score-Motor stops ? If so we then can say "The start-up / reset" is working --- and we can start having a look on "Why is the Ball not kicked over to the Shooter Alley ?".

Quoted from rolf_martin_062:

Problem "GI is flashing": When the Tilt-Relay faulty pulls-in: This cuts the Self-feeding of the H-Tilt-Hold-Relay-Coil and as the H-Relay now let go it opens its switches that feed the playfield- and other lights.
Please unsolder the wire orange-white-red away from the "Coil of T-Tilt-Relay" so the T-Relay cannot pull-in --- then do testing - starting a new game - WHAT happens. Greetings Rolf
P.S.: The little trick of unsoldering the wire orange-white-red away from the "Coil of T-Tilt-Relay so the T-Relay cannot pull-in": It is easy to be done --- and later on "easy to solder-on the wire again".

Quoted from AlexF:

The game is "motoring out" as they call it. Fighting to complete the startup sequence but failing some where. Check out the start-up sequence on Clay's site for 1975 and later Gottlieb.
http://www.pinrepair.com/em/index3.htm#start

Quoted from rolf_martin_062:

Hi WhiskeyTango
thanks for post-52 and the pictures in the post. We must come back to this post (stepping on the Player-Unit) --- but now - for the moment the T-Tilt-Relay: The colors (You mentioned) of the two wires are "almost right" - the colors of these wires in the schematics are called Red-Black and Yellow-Black. See the first JPG in post-47, at "my green-number-1" --- BUT these are wires on the SWITCH on T-Relay. I was writing about wire-color-orange-white-red - soldered-on at one lug of the COIL / of the elektro-magnet in this T-Tilt-Relay.
In Your picture I see on one side of the COIL two wires-color-black - the other lug on the coil has wire-color-orange-white-red --- THIS wire to be unsoldered --- by that unsoldering: The COIL can not get current and therefore cannot get magnetic - can not pull --- as we want this COIL to never pull. Greetings Rolf
P.S.: Your National Holiday is the fourth of July --- in Switzerland we have the first of August --- and it is almost over - we have past hour 23:15 - time for me to go to sleep - till tomorrow.

Quoted from AlexF:

You know I didn't have a schematic to work with. I usually like the shotgun approach. Go through clean and adjust everything properly and it should work. That usually gets you close but you also discover things with that strategy. I found a disconnected wire on the AX and thought that would do it but there was more going on. I seem to remember the "O" relay and the AX being a combined problem with my start sequence.
What helped me most was reading a couple troubleshooting posts related to the start-up sequence for 300 on RGP. I think someone had a similar problem as I did. Posted by the late great Al Garber if I remember correctly.
Guys willing to help with a schematic can usually get you narrowed down to specific areas to focus on. That helps a lot if you want to fast-track it.

Quoted from HowardR:

Here's the circuit that energizes the O (Ball Return) relay. A likely suspect is the anti-cheat switch which is probably on the bottom board.

Quoted from rolf_martin_062:

Hi Shaun
this post is not really about troubleshooting - I stick to the problem "faults on Score-Drums may hinder the pin to make it through the Start-up procedure" --- some loud thinking of me - You may think of doing some of the described jumperings.
On top, left of the JPG I show (my words) "simple jumpering" and "de luxe jumpering". The simple jumpering is ONE Jumper-Wire making an wanted connection --- permanent connection. This works fine in many situations --- but maybe the problem is tricky and we want to be part of the logic - helping the pin - at a specific time we do for a short period of time "Connection" --- then we cut the connection. So the "de luxe jumpering": I take TWO long Jumper-Wires - I take the free end of both wires through the open Coin-Door out into the open --- at the time I want connection: I hold one wire on the insulation --- I hold the other wire at the insulation - and I tip together the two blank ends.
A "super de luxe jumpering" is: I mount an door-bell type push-button - and I comfortably just push my doorbell pushbutton.
Different Jumperings - the 1,2,3,4,5,6,7,8:
I may say "I am not interested in the Score-Drums to fully reset - I take what I get - BUT I want the Player-Unit to step to Home-Position, So I establish the permanent jumper "1".
I may say "I am not interested in the Score-Drums to fully reset - I take what I get - BUT I want the Player-Unit to step to Home-Position, So I establish the permanent jumper "2".
Whats the difference in "1" and "2" ? They are almost the same - the difference is: When doing "1" I also jumper the connecting "wire of color brown-white-red" --- doing "2" I use the original wire "wire of color brown-white-red" in the pin --- IF (if, if) I do once the "1" and then the "2" and I get different results: I am told: There is a problem in the pin in that "connecting wire of color brown-white-red".
I may say "I am not interested in the Score-Drums of Player-2 - I am only interested in the Score-Drums of Player-1 (and then later Player-3 and Player-4)" --- so I establish the "3" or the "4".
Whats the difference in "3" and "4" ? It is the same difference as in "1" and "2" - the connecting wire (here of color white-slate).
I may say "I am not interested in the Score-Drums of Player-2 - I am only interested in the Score-Drum of Player-1 (and then later Player-3 and Player-4) --- ONLY Score-Drum 'the 10000's Score-Drum of Player-1". So I establish jumpering "5".
I may say "I do all or some of the jumpering "6" and or "7" " --- I can get informations on the connecting wires in the pin I can get infrmaion of a specific switch I just have jumpered.
A question - when I do the jumpering "8" --- WHAT is the difference to "doing the '4' " ?
Well - maybe in the pin there is a fault in the connecting wire color-black-white-red - connecting to SWITCH on the Z1-Relay --- doing once the "4" and later the "8" and I get different results: This tells me about this connceting wire.
When the pin is early in the Start-up procedure - has not yet reached position-20 (on the Player-Unit): The not-yet pulling Z1- and Z2-Relays therefore have the switches closed --- along my "red wiring" the Score-Drums-Switches (ALL) are bypassed --- the Player-Unit steps and steps and steps caused by the pulsing Score-Motor-Switch-1A. THEN The Player-Unit reaches position-20 (marked brown) - Z1-Relay pulls-in and opens its switch - NOW the Score-Drums of Player-1 and Player-2 must step forward to Zero so ALL their switches close --- current can pass - Add-Player-Unit-Coil fires - the Unit steps a step forward to position-21 and the stuff with Player-3 and Player-4 Score-Drums is taking place. And after that is done: "Z1- and Z2-Switches" are both closed again --- happily / rapidly stepping to Player-Unit-HOME-Position.
Greetings Rolf

Quoted from rolf_martin_062:

Hi Shaun
that kind of Time-Gap between Europe and the USA somtimes is awful - by now in Europe we have just 15 minutes past midnight ...
Just very short: HowardR is working with You on the Problem of O-Relay --- so it is better when I stay out --- with my post-60 I just wanted to show "techniques using a Jumper-Wire" --- You may buy another pin and another and another --- the use of Jumper-Wires is VERY helpful --- a) we must have an schematics, b) we must study the schematics and say "I want to test this", c) exactly do this test, d) analyze the result, e) maybe do a slightly different testing (think of the post-60 "1" and "2", "4" and "8". Greetings Rolf

Quoted from D-Gottlieb:

The EOS switch on a decagon score reel is not necessary for proper operation. The events that trigger the score reel end quickly enough anyway. If you have jumpered it closed than you have introduced another issue.

Quoted from HowardR:

Here's the circuit that energizes the O (Ball Return) relay. A likely suspect is the anti-cheat switch which is probably on the bottom board.

Quoted from D-Gottlieb:

The EOS on a solenoid is there to break the current to the solenoid as the stroke is completed. Pop bumpers, for example, will lock on until the stroke of the bumper is completed even if the triggering event (the ball hitting the ring switch) is of such a short duration that the bumper would not activate fully if the eos was not present in the circuit. When the bumper completes its stroke it opens the eos that kills the solenoid circuit and allows the bumper to retract. Scoring events are by pops, spinner, cushion or by score motor in this machine. The cushions and spinner will 99% of the time be closed by the ball long enough for the score reel solenoid to fully cycle, 100% for the score motor and pops. That is all the eos does here. On flippers it does some thing else, but lets leave that for now as that is not the issue here.

Quoted from D-Gottlieb:

Btw, are you certain that tbe AX relay is adjusted correctly? It has make/break contacts that can be very sensitive.

Quoted from D-Gottlieb:

If the jumpers were actually across eos switch contacts, all that would happen is the reel solenoid would stay energized once triggered during a scoring event, I am not sure whether that would apply during the reset sequence. Does the player unit operate at all with the jumpers removed? Can you upload a video to youtube? If you move scoring reels from zero at each player do they reset?

Quoted from D-Gottlieb:

So those were not eos switches but contacts. Probably zero contacts. There is only one eos per reel. You will see a couple of switches in the reel assembly with double contacts to increase reliability. Any switch that operates with the position of the score reel is not an eos switch. Congratulations on your progress. I would next check the trough switch between the out hole and the shooter lane.

Quoted from rolf_martin_062:

big question: Were You jumpering on "my orange 2" place ? Greetings Rolf

Quoted from rolf_martin_062:

Hi Shaun
Ball count does not increase: The fault can be several places --- the first thing to look is the U-First-Ball-Relay. In a working pin this happens: You toggle-on the pin and the U-Relay starts pulling and stays pulling. You start a game and in the Reset-Stuff happening the U-Relay quits pulling (see "encircled green" on the bottom of the JPG). The pin kicks out the very first Ball. You launch the Ball and You make some points --- Switches on the actuating N- and/or M-Relay make the U-Relay pull-in and the U-Relay stays pulling for the rest of the lifetime of this ball --- acrually: For the rest of the Game.
In Your pin ? (also look at the switches on U-Relay - all good ?)

Quoted from Newport-Bill:

Shot in the dark but whenever I had issues with my 300 it always was a result of the tilt switch in the upper right backbox. Probably not your issue but easy to check.

Quoted from D-Gottlieb:

I am thinking I said this early on. Glad it worked out.